Detecção e aspectos epidemiológicos de filarídeos em cães na região metropolitana de São Luís - MA

Abstract

Canine filariasis are diseases caused by filarial nematode parasites that belong to the order Spirurida. Among those involved, Acanthocheilonema reconditum and Dirofilaria immitis are the most prevalent canine filarids in Brazil. A. reconditum is a parasite that inhabits the subcutaneous, perirenal and peritoneal cavity tissues of dogs and is transmitted through flea bites. Based on the scarce number of publications on the subject and due to the little attention given by veterinarians in the country, an infection by this filarid is still underestimated. D. immitis, the etiologic agent of heartworm disease, is a parasite that causes severe and potentially lethal infection in dogs. It is transmitted to hosts by Culicidae, with emphasis on the genera Aedes, Anopheles and Culex. Intended for its zoonotic potential, a heartworm disease has been arousing interest in public health. The objective of this work was to carry out a survey of the occurrence of filarids in dogs residing in the city of São Luís, state of Maranhão. The study was developed from the blood of dogs treated at the Veterinary Hospital of the State University of Maranhão, in veterinary clinics and at home. Risk factors associated with the transmission of the parasite were also collected based on an epidemiological questionnaire. Blood samples from 103 dogs were submitted to microfilariae investigation using the Thick Drop technique, modified Knott method and detection of D. immitis antigens by lateral flow immunochromatography. The exposed ones were also subjected to molecular detection by the Polymerase Chain Reaction (PCR) technique and sequencing for differentiation and confirmation of the species. Eight (6.9%) were positive for the presence of filarids, of which six (5,8 %) were detected by the thick drop technique, six (5,8 %) by the modified Knott method, seven (6,7 %) by immunochromatographic test (Kit Alere Dirofilariasis Ag Test) and seven (6,7 %) by Polymerase Chain Reaction (PCR). Data analysis collected the new identity with D. immitis and a sample was positive for a species A. reconditum, which confirmed for the first time the circulation of this parasite in the city of São Luís-MA. The results also showed that the characteristics linked to dogs and environmental conditions associated with the vectors, as well as the lack of knowledge of the population, represent the main risk factors for the spread of canine filariasis